In fact, Super Mario fans have come out and theorised that Luigi is transgender.
This theory came when Nintendo removed the Peach/Bowser sexy hybrid Bowsette from their universe. They directed fans to the New Super Mario Bros. U Deluxe website, where the description for the mythical Super Crown reads:
"When Toadette finds one of these, she can transform into the super-powered Peachette. (Sorry Luigi—only Toadette can use this item!)"
The fact that Luigi is singled out in that line has made fans jump to the conclusion that he wants to rid himself of his green overalls for something a little more feminine.
Daily Dot also reminded fans that the Super Mario World TV saw Yoshi refer to Luigi as "Mama".
Luigi loved that name SO much that he adopted it as his nickname and there is even a Know Your Meme about it.
In Mario & Luigi: Superstar Saga, Luigi changed into a dress to trick Bowsetta into letting Peach go.
He dressed as Peach again for the Super Mario Adventures comic, and finally, there is a line in Luigi’s Mansion where he wondered about putting on a dress. "These look kind of comfortable," he says. "No, I’ll stick with my duds!"
As you can imagine, this theory has caused A LOT of controversy, but thankfully, a lot of support.
We love and completely support you Luigi!